Cooling unit



D.E.RusHAUsER L99L176 COOLING UNIT Feb. 12, 1935.

Filed April l, 1933 .Patented Feb. l2., 17935 UNITED STATES PATENT `ov1=1=11l1-y Donald E. Rutisliauser, St. Louis, Mo.

Application April 1, 1933, Serial No. 663,889

5 Claims.

eral and more particularly to cooling units adapted for use in refrigerators used in display windows, refrigerator cars, cold storage rooms, house- 5 hold refrigerators, and units of similar type.

The cooling unit of a refrigerator of the type referred to consists in the main of a cooling coil or coils through which is passed a cooling agent.

of any well known kind. It is desirable that the 0 difference between the temperature of the cooling coils and that of the surrounding air in the cooling chamber be kept at a minimum. In order to increase the effectiveness of the cooling unit, that is, to hold the difference in temperature between the cooling coils and the surrounding air to a minimum, it has been common practice to provide heat absorbing plates, or ns, attached to the cooling coil forgthe purpose of increasing the effective heat absorbing area on which the air circulating in the cooling chamber might impinge and in some instances to direct the flow of air through the coil. One method used heretofore has been to provide a plate made from a single piece of metal in which a number of holes were formed, and then to insert through these holes the sections of pipe comprising the cooling coil. 'I'his method of construction required the use of a number of straight pieces of pipe and it was necessary, therefore, in order to complete the coil, to join these straight pieces at their ends with pieces of pipe bent as required, and sol dered, brazed or threaded to the straight pieces of pipe referred to. This method of construction has proved to be costly, and furthermore, has been unsatisfactory because of the fact that leaks ometimes develop at the points where the straight; and curved pieces of pipe are joined. These leaks usually develop after the unit has been placed in service, and result in great inconvenience and loss to the owner, and indirectly, to the seller and the manufacturer of the unit as well. This loss is occasioned by the fact that when such leaks develop it is necessary toY take the unit out of service and expend money on repairs. In addition, the foodstuis stored in the refrigerator are sometimes damaged or ruined through contanif ination from the cooling agent, or through decay because of lack of refrigeration.

One object of my invention is to provide a cooling unit having a cooling coil, and its complementary heat absorbing plates made in sections, so that in assembling the unit it will be unnecessary to insert-the pipe comprising the coil through holes or other openings in the plates,

My invention relates to refrigeration in genf and thus eliminate, or reduce to a minimum, the pipe connections referred to above.

A second object is to provide a cooling unit, which through the use of a sectional type of heat absorbing plate, can be manufactured at a lower cost than has heretofore been possible, and also will assure an intimate and permanent heat conductive connection between the coil and the plate. f

A third object of my invention is to provide a 1 cooling unit consisting of a number of banks of coils, each bank `comprising an individual cooling coil, and in which the banks may be assembled into a cooling unit of any desired size and shape withl a. minimum number of pipe connections.

Referring to the drawing, in which one embodiment of my invention is shown, and in which similar numerals are used to designate similar parts, Fig. 1 is a perspective view of a section of a heat absorbing plate; Fig. 2 is a cross section along .20 the line 2-2 of Fig. 4 showing a cooling unit, made according to my invention and having two coil banks. Fig. 3 is a section along the line 3-3 of Fig. 2, and Fig. 4 is a plan view of the assembly shown in Fig. 2.

The heat absorbing plates, as indicated above, are made in sections, one such section being shown in Fig. 1 and indicated by the numeral 1. These sections may be made of sheet metal of the desired composition and thickness, and areformed 30 so as to have two iianges extending longitudinally of the plate throughout its length and preferably, normal to the general plane thereof. I prefer that these flanges be formed integral with the plate by bending portions thereof into the desired 35 position.

Notches, or depressions 3, preferably of semicircular cross section are provided in both ilanges, the diameter of these notches being substantially the .same as the outer diameter of the pipe comprising the cooling coil. Preferably the notches in each flange are spaced equidistant from each other, the distance between the vertical center lines of the notches in the upper ange, for example, being the same as the distance between 4 the vertical center lines of the straight portions of pipe comprising the upper tier of one of the coil banks. Similarly, the distance between the notches in the lower ange is the same .as the distance between the straight portions `of Apipe 50 comprising the lower tier of one of the coilbanks.

It will be noted, however, that in this embodiment, the vertical center lines of the notches in the upper ange and the vertical center lines the notches in the lower ange do not coincide,

but that the vertical center lines of the notches in one flange are approximately midway between the vertical center lines of the notches in the other ange.

'I'he pipe comprising the coil is indicated by the numeral 10, the straight portions of pipe shown in Fig. 4 lying in a number of horizontal planes. Portions 11, 13, and 15, for example, lie in the up per plane, that is, in the upper tier of one of the coil banks, and portions 12 and 14 lie in the lower plane, or lower tier of the same bank.

Furthermore, the pipe comprising the two tiers lie in separate vertical planes, but the vertical planes passing through the center lines of the pipe comprising the upper tier of one coil bank also pass through the center lines of the pipe cornprising the upper tiers of other coil banks, and the same is true L as to the pipe comprising the lower tiers. The vertical planes passing through the pipe comprising the upper tiers of the various coil banks are spaced approximately midway between the corresponding planes of the pipe comprising the lower tiers. As explained above in connection with the description of the spacing of the notches in the plate section, the distance between these vertical planes corresponds to the distancebetween the vertical center lines of the notches 3. Furthermore, the distance between a horizontal plane passing through the center lines of the portions of pipe 11, 13, and 15 and a horizontal plane passing through the centerlines of the portions of pipe 12 and 14 is equal to the distance between the outer faces of the flanges of a section of the heat absorbing plate and successive coil banks are similarly arranged.

This arrangement is shown in Fig. 2. The end parts 16 of each coil bank are formed by bending the pipe comprising the coil as required, and since these end parts are integral with the straight portions of the pipe no connections are required between these end parts and the straight portions.

Having described the elements comprising the embodiment of my invention shown in the drawing and described herein, the method of construction of the coil and its complementary heat absorbing plates as explained below will be clear: The cooling coil is formed by bending a piece of pipe of the desired composition, length, and diameter so that the general shape of the resulting coil will be as indicated in the drawing. A mandrel may be used for this purpose, or any other equivalent means which will provide a coil wherein the portions of pipe of which it is made are accurately spaced horizontally and vertically with respect to each other. Such a coil, regardless of the number of convolutions, will have only two ends requiring connection to the pipes leading to the source of supply of the cooling agent, and these connections may be made by any of the usual means.

The required number of sections of the heat absorbing plates which are formed as shown in the drawing and described herein, are then interposed in desired positions between the portions of pipe comprising the coil, and since, as explained above, the notches in the plate flanges have been accurately formed so as to register with the corresponding portions of pipe comprising the coil, an intimate t will be obtained between the sections of plate and the portions of pipe comprising the coil. Furthermore, it is to be noted that my method of construction provides a relatively large area of contact between the plates and the coil, which greatly facilitates the ow of heat from one to the other. The spacing of the plate sections with respect to one another can be made as desired simply by moving the sections laterally to the desired position. Since the diameter of the notches in the plate flanges is equal to the outer diameter of the pipe comprising the coil, and since the notches have been accurately positioned with respect to the corresponding portions of pipe comprising the coil, the heat absorbing plates will have intimate and permanent contact with the outer surface of the pipe, and an eilicient means will be provided whereby the heat absorbed by the cooling plate from the air of the refrigerator will be transmitted to the cooling coil, and thus to the cooling agent circulating therein. If desired, however, this contact between the plate sections and the coil can be made by brazing or soldering the parts together. In either case, if found expedient, holding means in the form of clamps or some similar device may be used to bind the coilv and the plates ilrmly together so that the cooling unit may be held firmly with the various parts remaining in proper relation one to another.

It is evident that my invention permits the manufacture of cooling units of various shapes and sizes as desired for use in refrigerators of various types. Furthermore, the ratio between the area of the surface of the coil and the area of the heat absorbing plates can be varied so as to obtain the most eflicient relation between these areas by the simple expedient of varying the distance between the sections of the plate, and consequently, the number of plate sections used in the unit. If it is desired to provide a cooling unit consisting of more than one coil bank, any number of coil banks maybe made as described and assembled into a single cooling unit, in which case the plate sections would be interposed not only between the portions of pipe comprising an individual bank, but also between the adjoining portions of pipe of adjacent banks. Manifestly, the dimensions of the plate sections used in such an assembly might be the same as in the case of a single bank, so that a standard plate section could be used. The connections between individual coil banks would be provided by any of the usual well known means, but it is evident that a coil might be formed, if desired, from a single length of pipe, with more than two horizontal tiers of pipe, and thus the number of pipe connections might be further reduced.

While I.have shown and described herein one embodiment of my invention it is evident that changes might be made in the construction and method of assembly as shown in this embodiment without departing from the spirit of my invention. For example, the heat absorbing plate might extend beyond the upper and lower portions of the coil, in which case the upper and lower plate sections might be formed without upper and lower flanges, respectively. Furthermore, the spacing of the notches with respect to each other is immaterial, provided that the spacing is such as to correspond with the spacing of the portions of pipe comprising the coil. Again, if it is desired to more eiectually split up the currents of circulating air, the sections of plate interposed between adjoining banks of coilsI may be staggered vertically with respect to the sections interposed between the tiers of pipe of an individual bank. I contemplate these and other changes as will-not depart from the spirit of my invention, which in essence covers a cooling unit consisting of a coil, and complementary heat absorbing plates made in sections, adapted and arranged so that the cooling unit may be assembled without the necessity of inserting the coil through holes or other openings formed in the plates, and in rwhich an intimate and permanent heat conductive contact is formed between the coil and the plates.

It is evident that my invention covers a new and useful improvement in cooling units as used in refrigerators in that such units can now be provided in various sizes and shapes without the necessity of inserting the pipe comprising the cooling coil through holes or other openings in the heat absorbing plates, and that as a result of my invention it is now possible to provide such cooling units with a minimum number of pipe connections, and therefore to reduce the loss inherent in the use of such connections.

What I claim as new and desire to secure by Letters Patent, is: 1

l. A refrigerator cooling unit comprising a pipe coil adapted for the circulation of a cooling agent therein, and a sectionally formed heat absorbing plate, certain sections being adapted to be interposed between the convolutions of said coil, the sections of said plate having flanges formed along the longitudinal edges thereof, said flanges being provided with notches so formed and positioned as to register with the portions of pipe of said coil, whereby an intimate heat conductive contact between said plate and said coil is obtained.

2. A refrigerator cooling unit comprising a pipe coil having the pipe thereof arranged in convolutions and adapted for the circulation of a cooling agent therein, and sectionally formed heat absorbing plates, certain sections being adapted to be interposed between the convolutions of said coil, the sections of said plates being generally parallel to one another and approximately normal to the center lines of said pipe at the points of contact, and each section of said plate having flanges formed along the longitudinal edges thereof, said flanges being provided with notches of semi-circular cross section having a diameter substantially equal to the outside diameter of said whereby heat carried by the air impinging on said 4 plates will be transferred to said coil.

4. In a refrigerating coil composed of pipeso formed as to have straight portions generally parallel to one another arranged in banks and curved portions connecting said straight portions, a sectionally formed heat absorbing plate having its sections interposed between and carried by the straight portions of said coil, the sections of said plate having flanges formed along the longitudinal edges thereof,l said flanges being provided with notches of senil-circular cross section having a diameter substantially equal to the outside diameter of said pipe and so positioned as to have intimate contact with the pipe of said coil, whereby heat carried by the air impinging on said plates `will be transferred to said coil.

5. A refrigerator cooling unit comprising a pipe coil having the pipe thereof arranged in banks and adapted for the circulation of a cooling agent therein, and heat absorbing plates adapted and arranged to be interposed between the banks of said coil and in intimate heat-conductive contact therewith, said plates having their general planes parallel to one another and approximately normal to said pipe at the points of contact and being disposed laterally with respect to their general planes whereby air flowing through said coil and impinging on said plates will be stratified and brought intointimate contact with the surface of said plates.

DONALD E. RUTISI-IAUSER. 

